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Publication numberUS6449486 B1
Publication typeGrant
Application numberUS 09/318,678
Publication dateSep 10, 2002
Filing dateMay 25, 1999
Priority dateMay 27, 1998
Fee statusPaid
Publication number09318678, 318678, US 6449486 B1, US 6449486B1, US-B1-6449486, US6449486 B1, US6449486B1
InventorsPadmanabha R. Rao
Original AssigneePolaris Wireless, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Multiple location estimates in a cellular communication system
US 6449486 B1
Abstract
Technique for determining the location of a mobile unit in a wireless communication system and presenting it to a remote party. In a scenario with first and second position estimates, the first position estimate is presented within a first predetermined time interval of call setup between the mobile unit and the remote party, and, if the second position estimate is available for presentation to the remote party, the second position estimate is presented within a second predetermined time interval after presentation of the first position estimate. Else, status information on availability of the second position estimate is presented within the second predetermined time interval.
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Claims(9)
What is claimed is:
1. A method for presenting a first and second position estimate of a mobile unit to a remote party in a wireless communication network, the method comprising:
presenting the first position estimate within a first predetermined time interval of call setup between said mobile unit and said remote party; and
presenting the second position estimate within a second predetermined time interval after presentation of the first position estimate, if the second position estimate is available for presentation to the remote party,
else presenting a status information on availability of said second position estimate within said second predetermined time interval after presentation of said first position estimate to said remote party.
2. The method of claim 1 wherein the first position estimate is derived from the identity of the cell in which the mobile unit is located.
3. The method of claim 1 wherein the first position estimate is derived from a multitude of cell identities provided to the remote party by the mobile unit.
4. The method of claim 1 wherein the second position estimate is derived from the interaction of the mobile unit with the wireless network.
5. The method of claim 1 wherein the second position estimate is derived from a GPS receiver embedded in the mobile unit.
6. The method of claim 5 wherein the status information consists of the state of the GPS receiver in the mobile unit.
7. The method of claim 5 wherein the status information consists of the availability of satellite signals to the GPS receiver in the mobile unit.
8. The method of claim 5 wherein the status information includes the expected time of arrival of the second position estimate.
9. A method for presenting a first and second position estimate of a mobile unit to a remote party in a wireless communication network, the second position estimate being derived from a GPS receiver embedded in the mobile unit, the method comprising:
presenting the first position estimate within a first predetermined time interval of call setup between said mobile unit and said remote party; and
presenting the second position estimate within a second predetermined time interval after presentation of the first position estimate, if the second position estimate is available for presentation to the remote party,
else presenting, within said second predetermined time interval after presentation of said first position estimate to said remote party, a status information including the expected time of arrival of the second position estimate,
wherein if the second position estimate is available, the second position estimate is presented to the remote party at a time subsequent to presentation of the expected time of arrival,
else if the second position estimate is not available at said expected time of arrival a second status update is presented to the remote party.
Description
CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from the following U.S. Provisional Application, the disclosure of which, including all attached documents, is incorporated by reference in its entirety for all purposes:

application Ser. No. 60/086,950, filed May 27, 1998, of Paolo L. Siccardo and Padmanabha R. Rao, entitled “Multiple Location Estimates in a Cellular Communication System.”

BACKGROUND OF THE INVENTION

The present invention relates generally to telecommunications, and more specifically to wireless messaging systems.

In connection with mobile communication systems, it is becoming increasingly important to determine the location of the communicating Mobile Unit (MU). Various systems for locating are already well known. One solution that is readily available in most modem cellular systems is to use the ID of the cell from which the MU is communicating. Typically, this information is accurate to a resolution of several miles. Another solution is to compute the location of the MU based on the cellular network signaling parameters (angle of arrival, time delay of arrival, signal strength, etc.). This information is typically accurate to several tens of meters. Yet another solution is to equip the MU with a GPS receiver which then attempts to track the location of the MU as accurately as possible. Typically, GPS receivers can compute locations to within several tens of meters of accuracy. When combined with differential corrections, the accuracy can be improved to less than 10 meters with a high degree of probability, as is known to one skilled in the art.

As far as reliability is concerned the cell ID information is the most reliable, and is guaranteed to be available as long as the cellular network is functioning normally. The network signal based location computations are less reliable, since they are dependent on several conditions being true at the time of the call. For example, most schemes require the MU to have line-of-sight visibility to multiple cellular base stations. This is not always possible. GPS based location computation is also not always reliable since the MU may be in an environment where there is no penetration of the GPS satellite signals.

SUMMARY OF THE INVENTION

The present invention provides techniques for determining the location of a mobile unit in a wireless communication system and presenting it to a remote party.

According to one aspect of the invention, the multiple location estimates available, each with possibly different resolution, reliability and latency, are presented in a consistent manner to the remote party thus enabling it to provide a consistent level of service to the user of the mobile unit.

Thus, in a scenario with first and second position estimates, the first position estimate is presented within a first predetermined time interval of call setup between said mobile unit and said remote party, and, if the second position estimate is available for presentation to the remote party, the second position estimate is presented within a second predetermined time interval after presentation of the first position estimate. If the second position estimate is not available for presentation to the remote party within the second predetermined time interval, status information on availability of the second position estimate is presented within the second predetermined time interval.

In specific embodiments, the first position estimate is derived from the identity of the cell in which the mobile unit is located, from a multitude of cell identities provided to the remote party by the mobile unit, or from the interaction of the mobile unit with the wireless network. In some embodiments the status information includes the expected time of arrival of the second position estimate. In specific embodiments, the second position estimate is derived from a GPS receiver embedded in the mobile unit. In such embodiments, the status information includes one or more of the state of the GPS receiver in the mobile unit and the availability of satellite signals to the GPS receiver in the mobile unit.

In some embodiments, if the second position estimate is available, the second position estimate is presented to the remote party after presentation of the expected time of arrival, but if the second position estimate is not available at the expected time of arrival, a second status update is presented to the remote party.

In embodiments where additional position estimates are potentially available, a similar sequencing of presentation of position estimates and status information can be implemented.

According to another aspect of the invention, the prior art cell identity based location estimate is further refined by designing a mobile unit that is capable of capturing the cell identity values from other networks in its neighborhood. The captured values are transmitted over the communication network to the remote party where all the identified cells are overlaid on a map of the locality. The final location estimate is the region of intersection of all the identified cells. This estimate is typically superior to that obtained by transmitting only one cell identity to the remote party.

A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representative cellular communication system with a GPS receiver equipped Mobile Unit;

FIG. 2 illustrates the location estimate obtained by using cell ID information;

FIG. 3 illustrates how the location estimate can be improved by intersecting cells from more than one network; and

FIG. 4 shows a flow diagram of the Mobile Unit location presentation process.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The present invention provides a new method for computing the location estimate of an Mobile Unit (MU) in a cellular communication network and describes how such an estimate may be combined with other available location estimates and gracefully presented to another party remote from the MU.

FIG. 1 is a high level block diagram of a cellular communication network. A Mobile Unit 10 has a connection with a cellular Base Station 15, which in turn is connected to a Mobile Switching Center (MSC) 20. The MSC typically supports multiple Base Stations, all of which are generically labeled 15 in the Figure. Calls that need to go out of the coverage area of the MSC are carried by a PSTN network 25 to which the MSC is connected. The call is terminated at an Other Party 30. The Other Party may or may not be mobile. (Calls to other MU's within the coverage area of the MSC are routed to the appropriate Base Stations for onward routing to the MU. These calls do not pass through the PSTN; however, FIG. 1 is illustrative and assumes Other Party 30 requires the PSTN for connection to the MU.) The connection mechanism described above is valid regardless of who originates the call. The location of the MU is of interest to the Other Party for several reasons such as provisioning of prompt and efficient personalized services, dispatching emergency assistance personnel, tracking the movements of the MU, etc.

In the specific embodiment MU 10 is equipped with a GPS receiver that is designed to receive the RF signals from a GPS network 50 and extract information therefrom to compute its location. Location information generated by the GPS receiver is selectively transmitted by the MU to the Other Party.

In the prior art, the Other Party has access to three different estimates of the location of the MU. These three estimates are generated using different technologies and independently of one another. Furthermore their accuracy, reliability and time to generate also differ significantly.

The first estimate is obtained from the cellular network directly. It is the area of the cell that the MU is currently located in. This is better described with reference to FIG. 2 wherein a MU 60 is within the geographical coverage area of a network 62. The coverage area is divided into a number of cells, represented by a cell 65, the size and shape of each cell determined by the location and operational characteristics of a corresponding tower 68. When MU 60 is connected to the network, the latter knows the identity of the cell the MU is located in. In FIG. 2 this cell is marked as a cell 70, and the area of cell 70 is thus the resolution of MU 60's location estimate.

Typically, a cell is several miles across. Since the resolution of the cell ID based location estimate is no better than the size of the cell that MU 60 is located in, the resolution offered by this estimate is typically no better than several miles. The advantages of cell ID based location estimate are: (1) it is naturally available as part of the cellular infrastructure, (2) it is obtained as soon as the call is established, and (3) it is always available.

The second estimate is obtained by performing sophisticated calculations on the signal parameters exchanged between the MU and the cellular network during the duration of the call. This estimate is referred to in this description as Network Computed Location (NCL) estimate. Such calculations can be performed either in the cellular network or in the MU or jointly in both. This method of computing the location estimate is inferior to the cell ID based method in that it is less reliable and takes additional hardware and/or software to compute. The unreliability comes from the fact that there are situations where MU 10 may not have a sufficiently clear communication access to the cellular network to enable an accurate location estimate computation. It is, however, superior to the cell ID based method in that its resolution can be much better—typically of the order of several tens of meters.

The third estimate is obtained from the GPS receiver embedded in MU 10. Under software control in the MU this location estimate is transmitted to the Other Party via the cellular network. The GPS method of computing the location requires additional complexity in the MU as compared to either of the two methods described above. Similar to the second method described above, it is also not always reliable since GPS signals are not available everywhere. However, if the GPS signals are available, it is possible to refine the location estimate to an accuracy of better than 10 meters by applying differential corrections. A characteristic of the GPS based location estimate is that the time required to arrive at the estimate is not deterministic, since it depends on the initial state of the GPS receiver.

The present invention describes a new method of estimating the location estimate of the MU that has similar advantages as the cell ID based estimate described above, but with potentially superior resolution. The invention takes advantage of the fact that any given location typically falls under the coverage of more than one wireless communication network. The different wireless networks may not all comply with the same technology, although in some situations some of the overlapping networks may indeed implement a common technology. For example, in Europe it is common to find two or more GSM networks having overlapping coverage. There are other networks, not typically classified as “cellular”, such as DECT, as is well known to one skilled in the art, which also overlap in coverage with the GSM networks. In the US too, it is common to find more than one cellular network operating over a common geographical area. Of course, as is well known, the US has multiple cellular technologies such as AMPS, GSM, TDMA, and CDMA. Any combination of these networks may have overlapping coverage. In Japan, the PHS network is widely prevalent and overlaps in many areas with traditional cellular networks.

One of the basic features of all wireless networks is the concept of cell beacons. Cell beacons are essentially predefined signals transmitted by the network over predefined or determinable frequencies. The beacons are continuously transmitted. The purpose of the beacon is to make available certain basic information such as the identity of the network and of the cell to the MU's. This allows any MU in the cell's coverage area to be aware of the availability of the network as well as carry out certain pre-defined measurements such as signal strength. The format of the beacon signal is different for each communication standard, but for each standard it is well defined and publicly known.

In the prior art technology, an MU is designed to comply with a pre-determined set of communication technologies, and thus can operate in conjunction with only the corresponding networks. For example, an MU designed to operate with the US PCS 1900 GSM technology will be able to interact only with a US PCS 1900 GSM network. Similarly, a dual-mode MU designed to operate with CDMA and AMPS technologies can interact only with CDMA and AMPS networks. Additionally, the operation of the MU may be even further restricted, at the time of activation of service typically, to a pre-specified number of networks. For example, a particular network operator may restrict all MU's given to its subscribers to operate over only its network and possibly over the networks of some “friendly” networks. This means that a prior art MU only attempts to “listen” to the beacon signals emanating from the networks it is restricted to operate with and ignores the beacon signals emanating from other networks. The beacon signals are essential to the proper operation of the MU by enabling it to make vital decisions such as which frequency to use and which tower to communicate with. Reception of a particular beacon signal by the MU implies that the MU is either within or very close to the cell identified by the beacon.

The present invention extends the prior art by enhancing the MU's to listen to multiple beacons, even those that do not emanate from its network. This task is easier if the different networks employ the same technology (such as GSM, AMPS, CDMA or TDMA), since no added circuitry is needed in the MU to decode the other beacon signals. However, it is also possible to design MU's that can decode the beacon signals of networks that use a different technology than the MU's primary network(s). For example, an MU designed to operate with GSM technology can be straightforwardly augmented to decode the beacon signals emanating from a European DECT network.

As mentioned previously, the beacon signals contain various pieces of information; in particular, they contain the identity of the network from which they emanate and the cell in which they are broadcast. An MU designed in accordance with the principles of this invention captures as many beacon signals as it possibly can and extracts at least the network and cell identity values from each one of them. These values are stored in internal memory and updated as required, i.e., as the MU moves to different cells and/or finds new beacon signals.

Beacon signals are not the only means by which a network makes its basic information known to a mobile unit, as is known to one skilled in the art. In one embodiment, the mobile unit broadcasts a predetermined query message and awaits a response from the network. The network responds by broadcasting its information which is captured by the mobile unit. In other words, the mobile unit requests the beacon information from the network in this case.

Referring back to FIG. 1, in accordance with the invention, the network and cell identity values stored in MU 10's internal memory are also selectively transmitted to Other Party 30. This information is in addition to the previously mentioned three location estimates transmitted from MU 10 to Other Party 30. In accordance with this invention, Other Party 30 is equipped a priori with topology information of all the different networks available in the vicinity of MU 10. In particular, Other Party 30 has a database that contains, for each network, the geographical layout of the cells along with the identity of each cell. In further accordance with the invention, Other Party 30 is also equipped with the ability to overlay the cell-layout over a visual map of the region (say on a computer screen), thus enabling a human operator to exactly see the coverage of each cell.

On receipt of the beacon information from the MU, the Other Party extracts the network and cell identity values, and for each network highlights on the geographical map the identified cell. This is illustrated in FIG. 3 for the case when the MU captures beacon signals from two networks, a Network 80 and a Network 82 whose cells are drawn in dashed lines. In the illustration it is assumed that the MU communicates to the Other Party over Network 80. The beacon signal captured by a MU 83 from Network 80 indicates that it is within cell 84. At the same time, the beacon signal captured from Network 82 indicates to the Other Party that it is within a cell 86 of Network 82 (although it is not communicating over Network 82). In accordance with the invention, by superimposing the cell topologies of the two networks on the map and highlighting cell 84 of Network 80 and cell 86 of Network 82 the Other Party can improve the location resolution by inferring that MU 83 is located in the intersection of cells 84 and 86. This is illustrated by a highlighted region 90 in FIG. 3. A prior art MU communicating over Network 80 would ignore the beacon from Network 82, and thus the Other Party would not be able to derive a location estimate for the prior art MU that is better than the size of cell 84. Region 90 is smaller than either cell 84 or cell 86 and thus is a better estimate of the location of the MU.

For purposes of clarity, further reference in this description to the novel scheme described above is made using the phrase Multiple Beam Location estimate, or MBL estimate.

In situations where there is no additional beacon available the proposed scheme degenerates to the cell ID based estimate. The major advantage of this scheme is that it can be implemented with no additional hardware cost to the network infrastructure. If it is known in advance that the MU will be used in areas covered by multiple networks that use the same technology or technologies that it is designed to comply with (e.g., GSM, CDMA, etc.), then all the modifications required in a prior art MU to take advantage of the proposed scheme may be implemented in software. For example, a dual-mode MU that is capable of communicating over a CDMA and AMPS network can be augmented to capture the beacon signals from both networks without requiring additional hardware.

Referring back to FIG. 1, the present invention further provides a method for capturing the available location estimates of MU 10 and presenting them to Other Party 30 in such a manner that Other Party 30 can provide the requested services to MU 10 in an efficient manner. Presentation of location information to Other Party 30 is complicated by virtue of the fact that the available estimates are generated independent of one another, have different resolutions, are all not available at the same time, and have different degrees of reliability. In fact, the reliability decreases as accuracy increases. [It is noted that “reliability” is used to indicate probability of availability of the estimate, not necessarily the degree of trustworthiness of the estimate.] Thus, in order for Other Party 30 to be able to provide location based services to MU 10 on a consistently efficient basis, it not only needs to have the best estimate of MU 10's location in the shortest possible time, but also needs to obtain this information in a consistent manner. In other words, there should be no variability in the way the information is presented to Other Party 30, even though there is variability in the way it is generated.

FIG. 4 is a flow-diagram of one embodiment of this invention that shows how location information of MU 10 is efficiently presented to Other Party 30. The actual presentation medium is not of any relevance to this invention—it could be visual, as on a computer monitor screen, audible, or text based. For convenience, in the sequel, the word “display” and “presentation” are used interchangeably.

Soon after the connection between MU 10 and Other Party 30 is established as shown in Box 100, the first location estimate, namely MU 10's cell ID, is presented to Other Party 30. Since the cell ID information is obtained as part of the call setup process, the presentation of this information can be guaranteed to occur within a predetermined time interval. This is indicated by Box 105.

The NCL estimate is also generated by the cellular network and typically neither MU 10 nor Other Party 30 has any control over its availability and/or accuracy. Furthermore, neither can predict its availability. As a result, the NCL estimate is presented to Other Party 30 by the cellular network whenever it is available. This is shown by Box 106.

The MBL estimate is generated based on availability of multiple beacons at the site of the MU. This is not under the control of the MU. Even if multiple beacons are available, the accuracy of the estimate cannot be predicted. In situations where they are not available, the MBL estimate degenerates to the cell ID estimate, as described previously, and there is no need to present it to the Other Party. However, the MU can determine reasonably quickly, and within a predetermined interval of time, if indeed it has access to multiple beacons. This information can be transmitted to the Other Party and presented within a predetermined interval of time, as shown by Box 107. The exact mechanism of transmitting this information is not relevant to the invention and is therefore not described in detail here. However, one skilled in the art can appreciate that there exist several techniques for transmitting data over cellular networks, and any one of those techniques could be employed.

If multiple beacons are available, the MU captures the required information from each beacon and transmits it to the Other Party. The transmission can occur within a predetermined interval of time. The exact mechanism of transmitting the beacon information once it is available in the MU is not described here since it is well known to one skilled in the art. On receiving this data the MBL estimate can be computed and presented to the Other Party. This is shown by Box 108.

The availability of the fourth location estimate, namely from the GPS receiver in the MU, is also not under the control of the MU or the Other Party, however, the MU can predict quite accurately if and when the estimate will be available. If the MU is currently in an environment where there is no GPS signal available, the MU immediately recognizes this condition. If the MU is in an environment where it does have adequate access to GPS signals, then it can estimate the time required to compute the location. This time is not always the same and is in fact dependent on the state of the GPS receiver at the beginning, as is known to one with skill in the art. If the receiver is in “warm” state then it can obtain the location estimate (also called as “fix” in prior art) quickly (within a few seconds). On the other hand, if the receiver is in “cold” state, then it needs a lot of additional data from the GPS satellites, and the time to obtain fix can be several tens of seconds. The availability of GPS signals and state of the GPS receiver in the MU are transmitted over the cellular network to the Other Party and presented as described below.

After displaying the cell ID information to Other Party 30, information on the status of the GPS receiver at the time of call initiation is presented (Box 110 in FIG. 4). As mentioned above, availability of this information is under the control of the MU, and therefore, the time of its presentation can be set to occur within a predetermined window. Status information typically includes an indication of the state of the receiver (i.e., “warm”, “cold”, etc.), whether adequate GPS signal coverage is available, and expected time to obtain a fix. If a fix is not possible to obtain, as indicated by query Box 115, the Other Party is presented by the most recently obtained GPS location estimate along with the time of that fix (Box 120). This information may be used by Other Party 30 as appropriate. For example, depending on the time of the last fix it may be quite close to the MU's current location (as can be inferred by comparing this location estimate with the cell ID information previously obtained), and can thus be used for providing the service. On the other hand, if the last location was taken significantly in the past, and/or if the MU has moved substantially since that time, then it may not be very relevant to the Other Party.

If a fix is possible, and indeed if the final fix has already been obtained, the computed location estimate is displayed to the Other Party along with the time of the fix, as indicated by Boxes 125 and 130. On the other hand, if final fix has not yet been obtained, the expected time of availability (ETA) of the fix is displayed, as shown in Box 135. As described above, the ETA is easily computed based on the initial state of the GPS receiver. Along with the ETA, the last known GPS location estimate and its time is also displayed. Once the fix is obtained, the final location estimate is displayed along with the time (Box 130).

The embodiment described above offers an advantage to the Other Party in that the Other Party is presented with the MU's location estimate in a very consistent and logical manner. A coarse estimate in the form of cell ID is always presented first, and within a bounded time of call setup. The undeterministic nature of the most accurate location estimate, namely the GPS estimate, is completely compensated for by presenting to the Other Party at known and predetermined time instants, and in a predetermined sequence, the status of the GPS receiver, the ETA of the estimate, and finally, the actual location estimate itself. This enables the Other Party to provide any requested services in a consistent and efficient manner.

CONCLUSION

While the above is a complete description of specific embodiments of the invention, various modifications, alternative constructions, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5504492 *Aug 1, 1994Apr 2, 1996Honeywell Inc.Look ahead satellite positioning system position error bound monitoring system
US5666122 *Jul 11, 1994Sep 9, 1997Qualcomm IncorporatedMethod for rapid signal acquisition in a satellite communications system
US5907809 *Sep 20, 1996May 25, 1999Ericsson Inc.Position determination using multiple base station signals
US5955986 *Nov 20, 1997Sep 21, 1999Eagle Eye Technologies, Inc.Low-power satellite-based geopositioning system
US5970414 *May 30, 1997Oct 19, 1999Lucent Technologies, Inc.Method for estimating a mobile-telephone's location
US6021330 *Jul 22, 1997Feb 1, 2000Lucent Technologies Inc.Mobile location estimation in a wireless system using designated time intervals of suspended communication
US6034635 *Jun 6, 1996Mar 7, 2000Gilhousen; Klein S.Method for using only two base stations for determining the position of a mobile subscriber in a CDMA cellular telephone system
US6052064 *Oct 30, 1997Apr 18, 2000Motorola, Inc.Method and apparatus in a wireless messaging system for dynamic creation of directed simulcast zones
US6163696 *Dec 31, 1996Dec 19, 2000Lucent Technologies Inc.Mobile location estimation in a wireless communication system
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7104870 *Jan 21, 2004Sep 12, 2006Zhang-Hua FongModified radial motion (MRM) method for modifying lengthwise curvature of face-milling spiral bevel and hypoid gears
US7149534 *Jan 23, 2001Dec 12, 2006Ericsson Inc.Peer to peer information exchange for mobile communications devices
US7236091Feb 10, 2005Jun 26, 2007Pinc SolutionsPosition-tracking system
US7245215Feb 10, 2005Jul 17, 2007Pinc SolutionsPosition-tracking device for position-tracking system
US7321305Jul 5, 2005Jan 22, 2008Pinc SolutionsSystems and methods for determining a location of an object
US7432923 *Jan 8, 2007Oct 7, 2008Vodafone Group PlcPosition measuring method and mobile communication terminal
US7580381Mar 4, 2004Aug 25, 2009Alcatel-LucentDetermination of the positions of mobile communication terminals with the aid of navigation data of various origins
US7613469 *Feb 26, 2003Nov 3, 2009Nokia CorporationPositioning-triggered handover
US7672675 *Sep 10, 2002Mar 2, 2010Sirf Technology Inc.System of utilizing cell information to locate a wireless device
US7945271Jul 19, 2007May 17, 2011Sprint Communications Company L.P.Location inference using radio frequency fingerprinting
US7962152May 24, 2007Jun 14, 2011Virgin Mobile Usa, L.P.Location determination for wireless mobile devices
US7970419 *Aug 16, 2007Jun 28, 2011Virgin Mobile USA L.L.C.Systems, devices and methods for location determination
US8000723Feb 12, 2010Aug 16, 2011Sirf Technology, Inc.System of utilizing cell information to locate a wireless device
US8010134 *Mar 14, 2007Aug 30, 2011Sprint Communications Company L.P.Architecture for mobile advertising with location
US8103289May 20, 2011Jan 24, 2012Sirf Technology, Inc.System of utilizing cell information to locate a wireless device
US8121619 *May 20, 2011Feb 21, 2012Google Inc.Geographic location information updates
US8180371Aug 18, 2009May 15, 2012Sprint Communications Company L.P.System and method for mobile device self-location
US8233879Apr 17, 2009Jul 31, 2012Sprint Communications Company L.P.Mobile device personalization based on previous mobile device usage
US8244236Aug 17, 2010Aug 14, 2012Wavemarket, Inc.System and method for aggregating and disseminating mobile device tag data
US8265618Oct 24, 2006Sep 11, 2012Wavemarket, Inc.Mobile service maintenance management
US8355737Mar 20, 2006Jan 15, 2013Wavemarket, Inc.Enhanced mobile location
US8359044Mar 20, 2006Jan 22, 2013Wavemarket, Inc.Enhanced mobile location method and system
US8369871Apr 4, 2012Feb 5, 2013Sprint Communications Company L.P.System and method for mobile device self-location
US8374575Mar 22, 2006Feb 12, 2013Jeffrey D MullenSystems and methods for locating cellular phones and security measures for the same
US8374784Aug 3, 2011Feb 12, 2013Andrew LlcSystem and method for determining the geographic location of a device
US8378888Feb 28, 2012Feb 19, 2013Andrew LlcSystem and method for determining the location of a mobile device
US8380220Nov 22, 2011Feb 19, 2013Andrew LlcSystem and method for generating a location estimate using a method of intersections
US8380222Feb 14, 2012Feb 19, 2013Andrew LlcSystem and method for multiple range estimation location
US8391884Mar 26, 2009Mar 5, 2013Andrew LlcSystem and method for managing created location contexts in a location server
US8400358Apr 15, 2009Mar 19, 2013Andrew LlcMethod to modify calibration data used to locate a mobile unit
US8406753Feb 5, 2008Mar 26, 2013Andrew LlcSystem and method for generating a location estimate using uniform and non-uniform grid points
US8457626Aug 13, 2012Jun 4, 2013Wavemarket, Inc.System and method for aggregating and disseminating mobile device tag data
US8462769Mar 26, 2009Jun 11, 2013Andrew LlcSystem and method for managing created location contexts in a location server
US8463285 *Apr 10, 2006Jun 11, 2013Wavemarket, Inc.Systems and methods for mobile terminal location determination using profiles of radio signal parameter measurements
US8463293Sep 11, 2012Jun 11, 2013Andrew LlcSystem and method for a high throughput GSM location solution
US8467805May 8, 2009Jun 18, 2013Andrew LlcSystem and method for determining a reference location using cell table data mining
US8489122May 20, 2011Jul 16, 2013Andrew LlcSystem and method for total flight time ratio pattern matching
US8504077Dec 4, 2010Aug 6, 2013Wavemarket, Inc.System and method for monitoring and disseminating mobile device location information
US8526968Feb 14, 2012Sep 3, 2013Andrew LlcSystem and method for mobile location by dynamic clustering
US8532024May 17, 2006Sep 10, 2013Andrew LlcMethod and apparatus for determining coupled path loss
US8548492Nov 22, 2010Oct 1, 2013Andrew LlcSystem and method for locating WiMAX or LTE subscriber stations
US8595070Jul 17, 2007Nov 26, 2013Sprint Communications Company L.P.Coupon validation using radio frequency fingerprinting
US8620346 *Sep 26, 2011Dec 31, 2013Qualcomm IncorporatedIntegrity monitoring in a position location system utilizing knowledge of local topography
US8638259Sep 1, 2010Jan 28, 2014Maple Acquisition LlcMethod and system for providing assistance data for A-GPS location of handsets in wireless networks
US8689277Sep 28, 2010Apr 1, 2014Andrew LlcMethod and system for providing location of target device using stateless user information
US8700069Apr 10, 2006Apr 15, 2014Wavemarket, Inc.Systems and methods for mobile terminal location determination using radio signal parameter measurements
US8718673May 20, 2011May 6, 2014Maple Acquisition LlcSystem and method for location assurance of a mobile device
US8730932Aug 5, 2009May 20, 2014Andrew LlcSystem and method for hybrid location in a CDMA 2000 network
US8731457Nov 22, 2010May 20, 2014Andrew LlcSystem and method for locating WiMAX or LTE subscriber stations
US8737985Nov 26, 2008May 27, 2014Wavemarket, Inc.Methods and systems for zone creation and adaption
US8762519Sep 18, 2009Jun 24, 2014Andrew LlcSystem and method for providing location services for multiple access networks from a single location server
US8787171Apr 7, 2009Jul 22, 2014Wavemarket, Inc.Efficient collection of wireless transmitter characteristics
US8787942Aug 5, 2009Jul 22, 2014Andrew LlcSystem and method for hybrid location in an LTE network
US8798613Sep 17, 2008Aug 5, 2014Wavemarket, Inc.Systems and method for triggering location based voice and/or data communications to or from mobile ratio terminals
US8805400Nov 22, 2010Aug 12, 2014Andrew, LlcSystem and method for locating WIMAX or LTE subscriber stations
US8812728Sep 14, 2011Aug 19, 2014Andrew LlcRouting requests for location-to-service translation (LoST) services using proxy server
US8848658 *Apr 15, 2010Sep 30, 2014Qualcomm IncorporatedInter-frequency indication of association data for multi-carrier wireless deployments
US8897813Feb 3, 2012Nov 25, 2014Andrew LlcLTE user equipment positioning system and method
US8907843Jun 24, 2008Dec 9, 2014U-Blox AgProcessing of satellite positioning system signals
US8938252Feb 5, 2008Jan 20, 2015Andrew LlcSystem and method to collect and modify calibration data
US8958754Sep 29, 2011Feb 17, 2015Andrew, LlcSystem and method for sub-coherent integration for geo-location using weak or intermittent signals
US8977760Nov 23, 2009Mar 10, 2015Commscope, Inc. Of North CarolinaSystem and method for routing SUPL proxy-mode traffice when multiple nodes are deployed in a network
US8990104Oct 27, 2009Mar 24, 2015Sprint Communications Company L.P.Multimedia product placement marketplace
US20100265913 *Apr 15, 2010Oct 21, 2010Qualcomm IncorporatedInter-frequency indication of association data for multi-carrier wireless deployments
US20120071172 *Sep 26, 2011Mar 22, 2012Qualcomm IncorporatedIntegrity monitoring in a position location system utilizing knowledge of local topography
US20130021199 *Jul 21, 2011Jan 24, 2013At&T Mobility Ii LlcEstimating network based locating error in wireless networks
CN100571467CMar 4, 2004Dec 16, 2009阿尔卡特公司Determination of the position of mobile communication terminals with the aid of navigation data of various origins
EP1494488A1 *Jul 1, 2003Jan 5, 2005Precisa Instruments AGMobile phone comprising position computation means
WO2003024131A1 *Sep 10, 2002Mar 20, 2003Lionel Jacques GarinSystem for utilizing cell information to locate a wireless device
WO2004082316A1 *Mar 4, 2004Sep 23, 2004Cit AlcatelDetermination of the position of mobile communication terminals with the aid of navigation data of various origins
WO2005006793A1 *Jun 7, 2004Jan 20, 2005Stephan AllemannMobile phone comprising position computation means
WO2006086398A2 *Feb 8, 2006Aug 17, 2006Pinc SolutionsPosition-tracking system
WO2007017691A1Aug 9, 2006Feb 15, 2007Applied Generics LtdA method of finding a physical location of a mobile telephone at a given time
WO2007047014A1 *Sep 20, 2006Apr 26, 2007Dhananjay S JoshiA method of obtaining a higher location precision of a wireless communication device
Classifications
U.S. Classification455/456.1, 455/440, 455/456.2, 342/352
International ClassificationG01S5/00, H04W64/00, G01S19/46, G01S19/25, G01S19/24, G01S5/14
Cooperative ClassificationG01S5/0045, G01S19/48, G01S2205/008, G01S5/0027, H04W64/00
European ClassificationG01S19/48, G01S5/00R2, H04W64/00, G01S5/00R1A
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Mar 25, 2004ASAssignment
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